Film guide for motion-picture machines



May 15, 1923. 1,455,367

T. F. UHL EMANN FILM GUIDE FOR MOTION PICTURE MACH INES 'FildiJune s. 1920 Patented May 15, 1923. v

UNITED STATES PATENT OFFICE.

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. FILE GUIDE FOB'MOTIONvPICTURE MACHINES,

To allwhomz'tmayaomem:

Be it lmown that I, Trmononn F. UHLn- MANN, a citizen of the' United States and-a resident of the city, county, and State of New York, have invented new and useful sprocket, which will prevent the film riding oil the teeth of the sprocket even though the sprocket holes be worn or mutilated.

. I have shown my improved-film guide as applied to the intermittent sprocket of the well-known motion picture machine known to the trade as Powers Camera ph and disclosed in United States glint No. 1,184,126, May 23, 1916, although it will be obvious that the device may be applied to other sprockets of the machine or to any film-feeding sprocket.

Referring to the drawings, I Fig. 1 shows in perspective the portion of said machine known as the framing carriage withmy improved film guide supported thereon in conjunction with the intermittent sprocket; through ming my improved film guide open to receive the film when the machine is to be threaded;

Fig. 3 is a similar view showing the film guide closed against thes rocket; and

Fig. 4 is a longitudina sectional view of by improved guide roller.

Referring to the drawings, 1 indicates the framing carriage which, as explained in the prior patent above referred to, is mounted for vertical movement beneath the projection aperture of the machine and carries the intermittently operated sprocket 2 for feedingthe film past the aperture, the framing carriage bein vertically adjustable in order to, frame t e picture into proper registration with the aperture. The film, which is indicated in dotted lines at 3, passes downwardly from the aperture over the sprocket and is held in engagement with the sprocket by a roller 4} carried by a pivoted bracket 5 in position for the roller to beheld against the under side of the h sprocket when the bracket is in the'closed Application filed June 3,

is provided with a lea'f-spri the sprocket.

length to maintain 1920. Serial n. 336,145.

position indicated in 3. The bracket 7 6 working in conjunction with the cam pro ection 7 so ar.

ranged that'the spring will hold the bracket lever in the open closed position of The roller4 is provided at each end with position of Fig. 2-or the grooved flanges which engage the margins of each side of the teeth of the the film on sprocket to hold the film on the sprocket teeth. The mechanism above describedis old and well-known and the structure disclosed is substantially the same as that shown in the above mentioned patent.

If all parts of the machine are pro adjustable and the film is in good condltion, the above described roller is sufiicient of itself to hold the film in engagement with in the normal'ope'ration of the machine the film will pull unevenly at the aperture, due to uneven tension on the shoes at the margins of the film or to sticking of thefilm at one side or'the other, or for various other rea sons, causing the film to shift laterally so that the teeth of the intermittent sprocket where they enter the sprocket holes do not exactly register with the sprocket holes, thereby causing the holes to be or the film to ride up on the sprocket teeth.

To prevent this operation I have provided the bracket 5 with an edge-guidi device to. engage the edges of the film at e point where the teeth of the sprocket enter the holes in the film, the guiding device acting to maintain the film 1n proper parallelism with the flanges of the sprocket so thatthe teeth register properly with the holes.

I have found, however, that unduly worn perly 7 0 My improved edge-guiding device comprises a rod .10 supported in ears at the edges of the bracket at the position shown.

Supported on the rod at the bracket is a'flanged roller 11 adapted the inner edge of to engage the margin of the film with its periphery and the edge of the film with its flange. A second flanged roller 12 ismountedon the rod 10 and pressed toward the roller 11 by means of a light spring 14 between the hub of the roller and the ear of the bracket.

'lihe two flanged rollers are separated by a sleeve 13 supported on the bracket and of a the flanges separated by lgistance equal to The operation of the device is follows.

the width of standard" It will be understood, however,

Q Lessee? g In the normal operation of the machine theedges of the film will be but lightly engaged by the flanges of the rollers, and as the rollers are free toturn on their rod they will add but little friction to the passage of the film through the machine and will be but very little worn by the en agement of the passing edge of the film. hould, however,

the film tend to pull sidewise, it willbe resisted by the flange of one of the other rollers, the 'sprin 14: being of suificient strength to hol the roller 12 against the tendency to lateral movement of the film. Should an imperfect splice or an unduly wide portion of the film reach the s rocket the sprin 14 permits the flange r0 lersto separate $01 the passage of the obstruction without damage to the film.

My improved film guide has been described in detail as it is at present applied to the above mentioned type of machine. v that the guide ma be applied with advantage to any filmceding sprocket, particularly the intermittent sprocket, and that the detailsv of construction ma be variously modified without departing rom the invention.

1 claim:

1. In a motion 1pliicture apparatus, the combination of a fi -feeding. sprocket below the pro'ector aperture and a pairof freely rotatalile disks su ported in position to engage the edges of t e film at the point where the sprocket teeth" enter the holes in a the film, said disks bein spaced apart a distance eqlual to the wi th of the film and yielding y held against lateral displacement to maintain the sprocket holes in'alinement with the path of movement of the sprocket teeth.

2. In a motion picture apparatus the combination of a film-feeding sprocket below the projector aperture, a bracket mounted for adjustment toward and from said sprocket, a pair of freely rotatable disks carried by said bracket for engaging the edges of the film, a separator between said disks for maintaining them separated a distance at least equal. to the width of the film, a spring for pressing said disks toward each other and ada ted to yield to permit a separa tion of t e disks for the passage of an ab normal width of film. a

3. In a motion picture apparatus, the combination of a film-feeding sprocket below the projector aperture, a pair of freely rotatable members adjacent the sprocket, for engaging the sides. of the film, and means for holdin said guides spaced apart a distance equa to the width of the film, said means yielding to permit the passage of an imperfect splice or abnormal width of film but resistingl lateral thrust due to sidewise pulling of t e moving film.

4. In a motion picture apparatus, the combination of a sprocket, guide means adjacent said sprocket for engaging the sides of the film, said means yielding to the pressure of an abnormal width of film but resisting ipteral thrpst due to sidewise pulling of the Signed at New York, in the county of New York, and State of New York, this 23rd day of December 1919. 

